JP2000306932A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a manufacturing method, wherein a resin can be applied to a wire-bond mounting section so that no voids remain within the resin without increasing the sealing region and application time, in a resin-sealed semiconductor device. SOLUTION: Semiconductor chips 21 to 26 mounted on a board 10 are wire- bonded to the board 10 with wires 30, after which first resin portions 40 are applied to connecting parts between the wires 30 and the board 10, using a dispenser in a manner filling the clearances between the wires 30 and the board 10. Thereafter, second resin portions 50 are applied onto the chips 21 to 26 using the dispenser, the resin portions 50 having a lower viscosity than that of the resin portions 40, and successively the resin portions 40 and 50 are cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device (hereinafter referred to as a resin-encapsulated semiconductor device) in which a semiconductor element wire-bonded on a substrate is sealed with a resin. A sealing method.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional general resin-sealed semiconductor device. In the resin-encapsulated semiconductor device J1, by performing wire bonding to the semiconductor element J3 mounted on the substrate J2 such as a printed board or a ceramic substrate, the semiconductor element J2 and the electrode portion of the substrate J1 are connected to each other. They are connected by wires J4 and are electrically connected.

[0003] Such a wire bond mounting portion composed of the semiconductor element J3 and the wire J4 is sealed so as to be surrounded by a resin J5 composed of an epoxy resin or the like. With this resin J5, a semiconductor element J3, a wire J4,
The connection portion and the semiconductor circuit portion are protected from an external environment such as heat, moisture, and vibration by sealing the electrode portion of the substrate J2.

FIG. 5 is a process chart showing a conventional method of manufacturing a resin-sealed semiconductor device J1, and is a process chart showing a resin-sealing method when a plurality of semiconductor elements J3 are mounted by wire bonding on a substrate J2. It is. In the resin-encapsulated semiconductor device J1, a liquid resin J6 is applied to the outer peripheral portion of one semiconductor element J3 by a dispensing method using a dispenser (such as a syringe), and then the same liquid is applied onto the semiconductor element J3. The resin J6 is applied by a dispense method. Then, after repeating this process for each semiconductor element J3,
The resin is cured by heat treatment or the like. Thus, the resin-sealed semiconductor device J1 shown in FIG. 4 is formed.

[0005]

By the way, in recent years, with the miniaturization of electronic equipment, as shown in FIG.
, The pitch of the wire J4 is becoming narrower and the length of the wire J4 is becoming shorter. When the above-described conventional resin sealing method is used for such a high-density wire J4, as shown in FIGS. 4 and 6, after the resin is applied, the wire J4 is located at the outer peripheral end of the semiconductor element J3. Voids (bubbles) remain in the portion B immediately below the wire J4 (the gap between the wire J4 and the substrate J2). This void is wire J4 for reliability.
Disconnection (open) and leakage between the wires J4.

Here, conventionally, as a means for preventing the generation of voids, there is a method of lowering the viscosity of the resin to be applied (reducing the viscosity of the resin itself or heating). In the case of this method, There is a problem that the low-viscosity resin easily flows on the substrate and the sealing area increases. An increase in the sealing area is not preferable for high-density mounting of the semiconductor device.

In addition, there is a method in which a thin needle is used as a dispenser and the dispenser is applied slowly over the entire area of the wire bond mounting portion. However, this method has a problem that the application time is lengthened. In view of the above problems, the present invention provides a resin-encapsulated semiconductor device in which a resin can be applied to a wire bond mounting portion without increasing voids in the resin without increasing a sealing area or application time. The aim is to provide a method.

[0008]

According to the present inventors, since the position where the void remains is mainly generated in the portion directly below the wire located at the outer peripheral end of the semiconductor element as described above,
The present invention was created by paying attention to changing the viscosity of the resin, the coating method, and the like between the step of applying to a wire portion other than the semiconductor element and the step of applying to the semiconductor element.

That is, according to the first aspect of the present invention, after the wire bonding is performed, the first connecting portion between the wire (30) and the substrate (10) is so filled as to fill the gap between the wire (30) and the substrate (10). A first application step of applying the resin (40) by using a dispenser, and thereafter, a semiconductor element (21)
To 26), a second application step of applying the second resin (50) using a dispenser in a state where the viscosity is lower than that at the time of application of the first resin, and And a curing step of curing the first and second resins.

According to this manufacturing method, in the first coating step, the first resin is applied to the connection between the wire and the substrate.
By applying by a dispense method so as to fill the gap between the wire and the substrate, no void remains in the resin immediately after the wire in the applied resin. Then, in the second application step, the second resin is applied by dispensing on the remaining semiconductor element in a state where the second resin has a viscosity lower than that at the time of application of the first resin, and a curing step is performed. Then, the resin is cured, and the resin sealing of the wire bond mounting portion is completed.

Here, in the above-mentioned conventional method, a step of coating a connection portion between a wire and a substrate at an outer peripheral portion of a semiconductor element is performed,
The coating step on the semiconductor element is performed using the same resin, but the coating step corresponding to the latter coating step is
In the present invention, in the second application step, a resin having a lower viscosity is used, and the spread of the resin to the application region can be accelerated, so that the application time can be reduced as compared with the related art.

In the first coating step, since the coating is performed by a dispense method so as to fill the gap between the wire and the substrate, the coating time is substantially the same as that of the related art when considered per unit coating area. Since the region is not the entire wire bond mounting portion but the connection portion between the wire and the substrate, which is a portion other than the semiconductor element, only a small region is required. Therefore, the application time including the first and second application steps is equal to or shorter than the conventional one.

In the first coating step, the peripheral portion of the semiconductor element is first surrounded by the high-viscosity first resin, so that the low-viscosity second resin is used in the second coating step. Can be prevented from flowing out of the second resin. Therefore, according to the present invention, a method of manufacturing a resin-encapsulated semiconductor device capable of applying a resin to a wire bond mounting portion without increasing voids in the resin without increasing a sealing region or application time Can be provided.

Here, as in the second aspect of the invention, in the second application step, if a dispenser having a larger needle diameter than the dispenser used in the first application step is used, the application time can be further shortened. In the invention according to claim 3, the first coating step and the curing step are performed as in the manufacturing method of claim 1, but in the second step performed between the first coating step and the curing step, Semiconductor element (21-2
6) The method is characterized in that the second resin (50) is applied by a printing method.

According to the present manufacturing method, similarly to the first aspect of the present invention, generation of voids and an increase in the sealing area can be prevented by the first coating step, and the coating time can be reduced as compared with the ordinary dispensing method. Using a printing method that is less affected,
By performing the second step, the coating time can be reduced.
The above object can be achieved. Further, in the invention according to claim 4, the first application step and the curing step are performed similarly to the manufacturing method of claim 1, but in the second step performed between the first application step and the curing step, The method is characterized in that the solid second resin (50) is disposed on the semiconductor element (21 to 26) and then melted to apply the second resin onto the semiconductor element.

According to the present manufacturing method, similarly to the first aspect of the present invention, generation of voids and an increase in the sealing area can be prevented by the first coating step, and the second resin is solidified in the second step. It can be applied simply by disposing and melting it as an object, and the application time is not affected by the application area. Therefore, the above object can also be achieved by the present manufacturing method. It should be noted that reference numerals in parentheses of the above-described units are examples showing the correspondence with specific units described in the embodiments described later.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 is a process diagram showing a method for manufacturing a resin-encapsulated semiconductor device according to the present embodiment, as viewed from above a mounting surface of a substrate on which a semiconductor element is mounted. This embodiment will be described as applied to a semiconductor device in which a plurality of wire bond mounting units are mounted on a substrate. Less than,
The description will be made in the order of the manufacturing process.

First, as shown in FIG. 1A, a substrate 10 on which a plurality of wire bond mounting portions are mounted is prepared. The substrate 10 is formed by forming an electrode portion (wiring portion) (not shown) on a resin printed board, a ceramic substrate, or the like, for example. On the substrate 10, a plurality (6 in the illustrated example)
Semiconductor chips (semiconductor elements according to the present invention) 21 to 26 are bonded and mounted with an Ag paste or the like.

The individual semiconductor chips 21 to 26 and the substrate 10
Are connected and electrically connected to the above-mentioned electrode portion by a wire 30 made of gold, aluminum or the like formed by performing wire bonding. The individual wire bond mounting portions including the semiconductor chips 21 to 26 and the wires 30 together with the electrode portions of the substrate 10 electrically configure a circuit.

Then, the wire 3 is placed on the prepared substrate 10 so as to fill the gap between the wire 30 and the substrate 10.
A first application step of applying the first resin 40 to a connection portion between the first resin 40 and the substrate 10 using a dispenser is performed, and then, when the first resin 40 is applied onto the semiconductor chips 21 to 26. In the state where the viscosity is lower than the state in
0 is applied using a dispenser.

More specifically, as shown in FIG. 1A, a high-viscosity hard resin such as an epoxy resin (first resin) is provided on the outer periphery of one side of the semiconductor chip 21 in the prepared substrate 10. A resin 40 (shown by hatching in the figure) is applied (dispensed) using a dispenser. At this time, the substrate 10 is desirably heated (for example, at 60 ° C.), so that the first resin 40 between the wires 30 is better wrapped around.

Next, chip 22, chip 23, chip 2
4, the coating is applied to the outer peripheral portion of one side of each of the chip 25 and the chip 26, and then to the outer peripheral portion of the next side of the chip 21 orthogonal to the one side, as shown in FIG. By repeating the same application (dispensing), as shown in FIG.
Is applied. These steps in FIGS. 1A to 1C are a first coating step.

Here, by applying one side to each of the plurality of chips 21 to 26, a time difference is provided between the application of one side and the next side of each chip, so that the wire 30 is surely connected to the other side. The first resin 40 goes around between the substrate 10 and the substrate 10, so that it is possible to prevent the occurrence of voids due to trapped air. Next, in the second coating step, as shown in FIG. 1D, a resin having a lower viscosity than the first resin 40 (the second resin, , 50 shown by dot hatching) using a dispenser.

As the second resin 50, for example, the same resin as the first resin 40 but having a low viscosity by increasing the solvent, or a resin different from the first resin 40 having a thixotropic coefficient By changing it, a material having a low viscosity can be used. Although not particularly limited, the first and second resins 40,
As 50, a combination that can be simultaneously cured in the curing step can be adopted from among the above-mentioned epoxy resins, acrylic resins, phenolic resins, and the like.

If the needle diameter of the dispenser used in the second coating step is made larger than that of the dispenser used in the first coating step, a larger amount of resin can be supplied at a time by that amount. Time can be shorter.
Thereafter, the first resin is integrated by the thixotropic property (viscosity) of the resin.
Then, the second resins 40 and 50 are cured by heat treatment (curing step). Thus, the resin sealing of each wire bond mounting portion is completed. FIG. 2 shows a schematic cross section (a cross section orthogonal to the substrate 10) of the completed semiconductor device after the resin sealing is completed.

According to the above-described manufacturing method, the first resin 40 is connected to the wire 30 and the substrate 1 in the first coating step.
In the first resin 40 after application, the portion directly below the wire 30 (indicated by the broken line in FIG. 2) is applied to the connection portion with the wire 30 by a dispense method so as to fill the gap between the wire 30 and the substrate 10. No void remains in the enclosed C section). In other words, for all the semiconductor chips 21 to 26, the outer peripheral portion is first applied, and then a time lag is provided for the chips 21 to 26.
Since the coating is performed on the upper surface 26, the first resin 40 sufficiently spreads to the portion directly below the wire 30, and can fill the gap between the wire 30 and the substrate 10.

According to the above manufacturing method, the second coating step is performed using the second resin 50 having a lower viscosity than the first resin 40, so that the spread of the resin to the coating region can be accelerated. As a result, the coating time can be shortened as compared with the related art. In the first coating step, the wire 30 and the substrate 10
Is applied by a dispensing method so as to fill the gap between the semiconductor chips 21 to 26. Since it is a connection portion between the wire 30 and the substrate 10 which is a portion other than the above, only a small area is required. Therefore, the application time including the first and second application steps is equal to or shorter than the conventional one.

Further, in the first coating step, the peripheral portions of the semiconductor chips 21 to 26 are first surrounded by the high-viscosity first resin 40. Even if the second resin 50 is applied, it is possible to suppress the second resin 50 from flowing out. Therefore, according to the present embodiment,
It is possible to provide a method of manufacturing a resin-encapsulated semiconductor device that can apply a resin to a wire bond mounting portion without increasing voids in the resin without increasing a sealing region and application time.

By the way, in FIG. 1 described above, resin sealing is performed for each of a plurality of wire bond mounting portions having substantially the same size and aligned. Even in the case of sealing, the above manufacturing method is applicable. FIG. 3 shows an example. In FIG. 3, the semiconductor chips 21 to 26 have different sizes and are arranged at random.

Even in the case where the sealing region is large, first, the first coating step (see FIGS. 3A and 3B)
Then, a first resin (hatched portion) 40 is applied to a connection portion between the wire 30 and the substrate 10 using a dispenser, and then in a second application step (see FIG. 3C). ,
A second resin (dot hatched portion) 50 is applied using a dispenser on the central portion of each of the chips 21 to 26 and the other region surrounded by the first resin 40. Next, a curing step is performed to complete the semiconductor device. (Other Embodiments) The second application step may be performed by a printing method. Specifically, the second resin 50 is made into a solution state in which the second resin 50 is dissolved in a solvent or the like, the substrate 10 is masked with a mask member or the like so as to open directly above the semiconductor chips 21 to 26, and the solution is squeezed or the like. What is necessary is just to apply.
In this case, the second resin 50 used for printing may have the same or different viscosity as the first resin 40.

Further, the second coating step may be performed using a solid resin (solid pellet) of a commercially available resin. This can be achieved by disposing solid pellets made of the second resin 50 on the semiconductor chips 21 to 26, melting them by heating or the like, and integrating them with the first resin 40.
In the printing method and the second application step using the solid pellets, the second resin 5 is used in comparison with the dispensing method.
Since the coating is performed without being greatly affected by the size of the coating area of 0, the coating time can be shortened.

Further, as a semiconductor device, even if a wire bond mounting portion, that is, one semiconductor chip is used,
The invention is equally applicable.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a resin-sealed semiconductor device according to the embodiment.

FIG. 3 is a process chart showing another example of the method for manufacturing the resin-sealed semiconductor device according to the embodiment.

FIG. 4 is a schematic sectional view showing a conventional general resin-sealed semiconductor device.

FIG. 5 is a process chart showing a method for manufacturing a conventional resin-encapsulated semiconductor device.

FIG. 6 is an explanatory diagram illustrating void generation in a resin-sealed semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... board | substrate, 21-26 ... semiconductor chip, 30 ... wire, 40 ... 1st resin, 50 ... 2nd resin.

Claims (4)

[Claims] A semiconductor device (21 to 2) is provided on a substrate (10).
6), and by performing wire bonding,
In a method for manufacturing a semiconductor device in which the semiconductor element and the substrate are connected by a wire (30), and then the semiconductor element and the wire are encapsulated by a resin, the method includes the steps of: A first application step of applying a first resin (40) to a connection portion between the wire and the substrate by using a dispenser so as to fill a gap between the wire and the substrate; and a first application step. After that, a second application step of applying a second resin (50) on the semiconductor element with a dispenser in a state where the second resin (50) has a lower viscosity than the state at the time of application of the first resin, And a curing step of curing the applied first and second resins. 2. In the second application step, the second resin (50) is applied using a dispenser having a larger needle diameter than the dispenser used in the first application step. A method for manufacturing a semiconductor device according to claim 1. 3. A semiconductor device (21 to 2) on a substrate (10).
6), and by performing wire bonding,
A method of manufacturing a semiconductor device in which the semiconductor element and the substrate are connected by a wire (30), and then the semiconductor element and the wire are sealed so as to surround the semiconductor element and the wire; A first application step of applying a first resin (40) to a connection portion between the wire and the substrate by using a dispenser so as to fill a gap between the wire and the substrate; and a first application step. Thereafter, a second application step of applying a second resin (50) on the semiconductor element by a printing method, and a curing step of curing the applied first and second resins are described below. A method for manufacturing a semiconductor device, comprising: 4. A semiconductor device (21 to 2) on a substrate (10).
6), and by performing wire bonding,
A method of manufacturing a semiconductor device in which the semiconductor element and the substrate are connected by a wire (30), and then the semiconductor element and the wire are sealed so as to surround the semiconductor element and the wire; A first application step of applying a first resin (40) to a connection portion between the wire and the substrate by using a dispenser so as to fill a gap between the wire and the substrate; and a first application step. After that, the solidified second resin (5
0) is disposed on the semiconductor element and then melted to apply the second resin onto the semiconductor element. Subsequently, the applied first and second resins are applied. And a curing step of curing the resin.